Certainly it now doesn't cause the problem which it caused for me a moment ago.

However, that means I now can't use it to debug the defence in my LJ style code, which I was just about to attempt :-) Perhaps I should write a private LJ entry in an attempt to reproduce it myself...

Are implicit closing tags not permitted these days, then? I was under the impression that they might be deprecated, they might not be valid XHTML, and they might be so 1990s dahling, but they still weren't technically illegal.

Ah, hm, sorry about that. But I suspect you're right and you're better off reproducing the bugs you want in a private journal entry!

I was thinking of XHTML (because that's what we do here, theoretically), indeed. Not sure if implicit closing tags are illegal, but they're definitely morally wrong. 8-) You can validate your HTML 4.0 here if you want, but I'm afraid I don't have the energy to test it (or ferret through documentation) at the moment... sorry, just too lazy!

Aha, I've reproduced the problem. My defence didn't trigger because you put a tag on this entry: the bit of HTML that handles tags appears to be glued on to the entry's own HTML before my style code gets to process it, which means my defence code didn't see </tr> at the end of that string because it was somewhere in the middle.

Sigh. I'm not even sure I can compensate for that in my style code, since it would require me to do a much fuller job of HTML parsing; I may just have to fall back to the traditional method of whinging at people who trigger the bug :-/

Certainly XHTML requires all tags to be closed explicitly. I'm under the impression that in HTML 4 the closing tags for <tr> and <td> elements are optional (though you always used to have to put them in anyway in order to avoid breaking Netscape 4).

LiveJournal is aiming for XHTML compliance, but that's a nonsense: you're never going to be able to massage random user-supplied HTML into syntactically valid XHTML (and syntactically invalid XHTML is completely pointless in my view). Indeed, the page into which I'm typing this comment has an HTML 4 doctype, so strictly speaking all the XHTML self-closing tags on this page are syntactically invalid. [See previous rant.]

Anyway. The point of LiveJournal's HTML cleaner is that it's supposed to protect the LiveJournal environment from the effects of any bad HTML appearing within your entry; so if you can break it, it's definitely a bug regardless of whether or not the HTML you typed happened to be valid.